1. Field of the Invention
The present invention relates to a spoken dialog system, and more particularly, to a method of and apparatus for rapidly and precisely managing a dialog turn between a user and an agent by using speech information, facial expression information, and delay time information, and a spoken dialog system using the method and apparatus.
2. Description of the Related Art
Agents are classified as software agents and hardware agents. The software agents generally work as an interface on a screen of a computer. The hardware agents are such as humanoid toys and humanoid robots or pet toys and pet robots. Such agents can converse with users in compliance with their embedded programs. In general, monotonous types of speech dialogs are made between the agents and the users. For example, the users answer the agents' questions, the agents answer the users' questions, or the agents carry out the users' commands. Also, since scenarios made by the programs embedded in the agents limit the dialogs' contents, the degree of freedom of speech dialogs is quite low. In addition, the users and the agents do not freely exchange speech dialogs, and thus the speech dialogs are unnatural.
As a conventional technique for overcoming the monotonousness and unnaturalness of speech dialogs, Japanese Patent Publication No. 2002-196789 suggests a speech interactive device which develops speech dialogs with a user based on a recognition standby time counted by a timer and a counter (i.e., a time from when a speech from the speech interactive device utters until the user recognizes the speech uttered from the speech interactive device). However, the speech interactive device starts working only after the recognition standby time has elapsed without the user's speaking. Thus, the speech dialog exchange between the user and the speech interactive device is not rapidly performed. As a result, the speech dialogs are delayed and the user feels bored.